Page 40 - The Veterinary Care of the Horse

given if they have a wound before their vaccination programme is complete. Tetanus

antitoxin is not a vaccine, but it gives immediate protection against tetanus for a few days.
VetBooks.ir Equine herpesvirus (EHV) vaccination programme

There is a vaccine available which gives protection against EHV-1 and EHV-4. Pregnant

mares are vaccinated during the 5th, 7th and 9th months of pregnancy to reduce the risk of
infectious abortion caused by herpesvirus.

Foals may be vaccinated from 5 months of age. Following the primary course when the
first and second injections are given 4–6 weeks apart, boosters are recommended every 6

months. Immunity following vaccination and natural infection is relatively short-lived, but
vaccination is considered to be beneficial.

Vaccination against strangles

A vaccine developed to protect horses against strangles is available. It is injected into the
mucosa on the inside of the horse’s upper lip. The primary course is 2 injections given 4

weeks apart. Foals can be vaccinated from 4 months of age. Whenever possible, all the
horses kept together in a group should be vaccinated at the same time.

Horses in high-risk situations (e.g. new horses regularly being introduced into the group,
horses that regularly attend competitions or horses close to an outbreak of strangles) may be

given boosters every 3 months. Those in medium-risk situations (e.g. occasional outings to
shows or lessons) can be vaccinated every 6 months. Horses that are kept in a group that do

not attend shows or otherwise travel where they may mix with other horses are generally low
risk and may not need vaccinating. Your vet is the best person to ask for advice as some

horses experience adverse reactions to this vaccine.

IF AN OUTBREAK OCCURS

If an outbreak of strangles occurs in the vicinity, any horse that has not had a booster within 3
months should be re-vaccinated. Provided the last injection was less than 6 months ago, a

single dose is sufficient. Only healthy horses should be vaccinated so the vaccine should not
be given if the horse is thought to be developing the disease. Thus it is not advisable to

vaccinate horses that have had been in contact with an infected horse.

PRECAUTIONS

Pregnant or lactating mares should not be vaccinated and this vaccine should not be

administered at the same time as other vaccines. Some horses experience temporary swelling